Field of the Invention
The present invention relates to gate valves and more particularly to swinging gate valves of the type wherein the gate or valve disk is urged against its seat by spring pressure and by material pressure in the line closed by the valve. In prior valves of this type, the passage of fluid through the valve body is controlled by port-sealing disks which are mounted in swing arms and which swing into and out of alignment with a port connecting the inlet and outlet conduits of the valve body. The port sealing elements and the mechanism for activating the sealing elements in valves of this type do not completely fill the space defined for the valve body. Frequently, sediment from the fluid passing through the valve becomes deposited within the valve body causing the valve to pack, inhibiting the opening and closing of the valve. This is particularly true in applications of the valve for coarse materials, such as iron, limestone, abrasive vapors, sludge, tar sand, slurries and other materials which tend to accumulate in the valve chamber. Besides the above problem, these rugged materials also tend to get between the valve seat and the cooperating sealing disk. This often results in damage to the valve seat and sealing disk due to the abrasive nature of these materials.
The problems associated with packing are greatly pronounced with swinging gate type valves because the sealing element is mounted to a swing arm adapted to be swung to seal and unseal the valve port. When the swing arm rotates it tends to compact sediment within the valve chamber, packing that sediment within the chamber, thereby rendering the mechanical operation of the valve difficult, if not impossible. When such a condition results, it then becomes necessary to remove the valve from the conduit and disassemble it so the sediment can be cleaned out. This practice is often extremely costly since many valves are so situated that it is necessary to shut down the flowline or completely drain the line before the valve can be removed and cleaned. Additionally, the facility being serviced by the valve is disabled pending completion of the valve servicing.
With the foregoing disadvantages in mind, the object of the present invention is to provide a packing-resistant valve which will preclude the depositing of accumulative sediment within the valve chamber. A further object of the invention is to form a valve in which the cleaning operation may be accomplished automatically and without the necessity of dismantling of the valve.
A still further object of the present invention is to provide a valve which greatly reduces the likelihood of sediment accumulation within the valve chamber.
Another object of the present invention is to provide a valve which maintains a clean seating surface.
A still further object of the present invention is to provide a valve which distributes the flow pressure better to the seating surface.
A still further object of the present invention is to provide a valve which prevents material build up in the valve chamber by inducing air pockets within the valve body.
A still further object of the present invention is to provide a valve which insures a tight port seal.
These and other objects and advantages of the present invention will become apparent upon a reading of the following detailed description, as well as the appended drawings and claims.